AC-AC power converters allow for flexible output power control in a variety of applications. Traditionally, power control for many AC loads is performed by duty cycle switching algorithms, which essentially skip entire line cycles, therefore regulating the output power without changing the peak output voltage. Presently, there exist solutions for AC-AC converters in the kW range. However, these solutions rely on an input switching stage, tank storage (such as in resonant converters), as well as an output switching stage (or inverter), and some solutions rely on a DC link. Implementing this solution in a “hazardous” area becomes costly and difficult. All of the existing solutions that both operate in the kW range and are commercially affordable rely on the use of an internal cooling fan, and such cooling fans are prohibited for use in power converters in hazardous areas. Specifically, the industrial heat tracing market does not allow for cooling fans in power converters in many crucial applications. Extending the present solutions for AC-AC converters with dialed-in peak voltage to heat tracing applications and hazardous area applications therefore becomes very costly.
Existing power converters are costly and many do not meet the requirements for use in the hazardous areas, and specifically for use in industrial heating tracing applications. Therefore what is needed is an improved power converter for use in hazardous areas.